Experts call for urgent conservation of the rodent species, and local delicacy, belonging to an 11-million year old family

Laotian rock rats (Laonastes aenigmamus) for sale at a market in Laos' Khammouan Province. Scientists in Vietnam found three dead specimens from the 11-million-year-old species in Quang Binh Province's Phong Nha Ke Bang National Park last week.

Scientists in north-central Vietnam have discovered a rare rodent species that was believed to have gone extinct 11 million years ago.

On September 6, Phong Nha Ke Bang National Park confirmed that a group of local scientists and specialists from the biodiversity conservation organization Fauna and Flora International (FFI) had found two dead members of a rare rock rat family at On Hamlet in Minh Hoa District's Thuong Hoa Commune, Quang Binh Province.

On September 11, Nguyen Xuan Dang of the Institute of Ecology and Biological Resources, found a third, which was also dead, in the same area.

Dang confirmed with Thanh Nien Weekly that the Ruc ethnic people in the region call the species Ne Cung. Local media had already called the rodent a variety of different names in recent reports. The word means rat-monkey in the Ruc language because of its appearance.

Actually, another dead rock rat had been found in Laos' Khammuan Province adjacent to Quang Binh in 2005. There locals call the animal Kha-nyou. Scientists then believed it belonged to a sole member of the new family Laonastidae (Laonastes aenigmamus) on the basis of its distinctive morphology and apparent phylogenetic isolation from other living rodents. They also called it the Laotian rock rat.

However, in 2006, Dr. Mary R. Dawson, curator emeritus of Vertebrate Paleontology at the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania, and a group of scientists said Laonastes is actually a surviving member of the otherwise extinct rodent family Diatomyidae, known from early Oligocene to late Miocene sites in Pakistan, India, Thailand, China, and Japan.

"Laonastes is a particularly striking example of the "˜Lazarus effect' in Recent Mammals, whereby a taxon that was formerly thought to be extinct is rediscovered in the extant biota, in this case after a temporal gap of roughly 11 million years," the group said in a Science Magazine article.

Dawson described the rodent as having a vaguely squirrel-like appearance, with an elongated head, pelage ranging from black to grizzled, and a long hairy tail.

Rat hunters

Following the discovery in Laos, Vietnamese scientists launched a series of searches for the animal in Quang Binh forests.

Vu Ngoc Thanh, Project Co-Director of US-based conservation NGO Douc Langur Foundation and General Curator of the Department of Vertebrate Zoology at the Biological Museum, said he has spent five years in Quang Binh's mountainous regions searching for the rodent.

"We even asked illegal loggers to notify us if they see such rodents," Thanh, who is studying biodiversity in Phong Nha Ke Bang, told Thanh Nien Weekly on the phone Tuesday (September 13).

Thanh and other scientists have also set several traps at possible rodent dens in and around On Hamlet.

"Locals have sold the rodents as food at markets in Laos," Thanh said, showing a series of photos of the rodents hung up at stalls at a Khammuan market.

Dang and another group of scientists from the Institute of Ecology and Biological Resources have been searching for the rodents around the national park for several years.

However, Dang said they knew they were closing in when some local Ruc people told them that they often trapped strange animals with a "rat's body, monkey's hair and a squirrel's tail."

A local resident took them to a house where they saw two of the rare rodents, already killed.

Million-year-old rodents as daily bread

Local residents in On Hamlet were surprised that scientists came to study a "rat" that they often trap and eat like any other rodent species.

They said the rodents only go out of their dens at night and are abundant in the rainy season from June to September. But they said their numbers had decreased a bit this year.

A resident said the meat of the rock rats is not as good as other rat species because it is too soft.

Luu Minh Thanh, director of Phong Nha Ke Bang National Park, said authorities were encouraging the Ruc community to stop eating the rare rodents for the sake of research and conservation.

Thanh of the Biological Museum said the rock rat should be listed on Vietnam's Red List of threatened species for better protection.

The International Union for Conservation of Nature added Laonastes aenigmamus as an endangered species when updating the 2007 list this year. It is considered to be facing a very high risk of extinction in the wild.

Nguyen Duy Luong of FFI said his group was conducting further research before announcing a report on the findings of the species in Quang Binh by November this year.